Passage Key, less than a mile north at the southerly entrance to Tampa Bay, has guided ships into the bay since Ponce de Leon explored this coast in 1513, when early Spanish explorers called it Bahia del Espiritu Santo. The island was named Isla de San Francisco y Leon by the Spanish in 1757, Burnaby Island by the English in 1765, and later Pollux Key, corresponding to nearby Castor Key at Egmont Key, before becoming known as Cayo del Paseje in 1783 during the second Spanish occupation, the origin of the present name. Once much larger, it had a fresh water lake surrounded by large trees. In the early 1830's it was the site of a fishing rancho operated by Baltimore sea captain William Bunce, later a haven for refugees seeking safety from marauding Indian war parties, and its probably spring-fed lake served as a watering station for coastal voyagers. In 1836 the U.S. Schooner Grampus and Revenue Cutters Washington and Jefferson anchored close ashore while their guns and shore parties protected settlers from the Indians. President Theodore Roosevelt designated Passage Key a migratory bird refuge in 1905. It later served for a time as the home of Captain Asa N. Pillsbury, Jr., a National Audubon Society warden, who reported 102 species of birds there in 1910 and remained warden until 1921, when during the night of October 25-26 a hurricane-spawned tidal wave caused the island to disappear. Since then it has gradually re-emerged and is once again a sea bird sanctuary, declared part of the National Wilderness Preservation System by the U.S. Department of Interior.